Owing to the massive amount of data accumulated through various genome-wide sequencing and gene expression projects, there is an urgent need to develop novel bioinformatic tools and technologies to uncover the functions of each gene in the human genome. Recent innovations in gene knockdown technology, based on small interfering RNA (siRNA), have revolutionized gene functional analysis. It is now possible to design RNA interference experiments to target every gene in the genome and screen for specific phenotypes. The ultimate goal of the proposed project is to develop and make available, in the public domain, software for the prediction of effective siRNAs and a database with a functionally verified set of siRNAs for all currently discovered human, mouse and rat genes. Phase I of this program will cover the development of an algorithm for predicting the most efficient siRNAs and a high-throughput technology for the analysis of the silencing efficiency of the predicted siRNAs for several model mRNAs. At the Phase II, the program will be extended towards the development of a database with a genome-wide set of functionally verified human, mouse and rat siRNAs. Another goal of the Phase II studies is to release, as commercial products, a functionally verified collection of siRNAs and genome-wide siRNA libraries cloned in lentiviral vectors. The collection of siRNAs and siRNA libraries in lentiviral vectors will allow the performance of a global search for functional genes involved in a variety of diseases and to validate new drug targets by arbitrary selective inactivation of specific mRNAs and corresponding proteins in the context of the living cells. [unreadable] [unreadable]